2009-2014 Cadillac CTS-V General Discussion Discussion, 09 CTS-V LSA Engine -> 09 ZR-1 LS9 Engine in Cadillac CTS-V Series Forum - 2009-2014; So does anyone with more knowledge of engines than I think that you'll be able to upgrade (aftermarket) the LSA ...

Re: 09 CTS-V LSA Engine -> 09 ZR-1 LS9 Engine

So does anyone with more knowledge of engines than I think that you'll be able to upgrade (aftermarket) the LSA engine to more closely match its more powerful sibling the LS9?

Chris

i am sure many here know more than i... but here is my answer.

yes and no. some of the components used on the LS9 were done in part to allow it to fit within a Vette and reduce weight (ex: dry sump). this doesn't carry over to the V2 but doesn't really make much difference for a sedan.

the blower on the LS9 is rated for higher boost, so that is an easy upgrade and i would bet anyone lunch that it appears on the V2 by the 2011 model year.

other than that, the LS9 is hand built to spec. i'm not sure what this really means as opposed to the LSA, it is not like either are run of the mill production motors. forced induction motor require very stout internals unless GM wants to provision for huge warranty costs. so the LSA should respond extremely well to upgrades, moreso than the LS2 or LS6 in the V1.

dumb question: i assume they are similar or very close in displacement. so there is no substantial upside to changing motors like there was with the LS7 upgrade that i saw someone do on this board.

Re: 09 CTS-V LSA Engine -> 09 ZR-1 LS9 Engine

The ZR1 has forged pistons which can handle the extra power. The V pistons are not forged and therefore if you add too much hp the engine might not be able to handle it and can result in damage to the engine. Thats one of the reasons why the ZR1 has a different supercharger that prdocues more power. OR FOR A MORE DETAILED EXPLANATION READ THIS:

We've now had a couple of weeks to digest the new 620+hp LS9 V8 in the Corvette ZR1, it's time to see what else the GM Powertrain team has up its sleeves. The other half of the GM power duo to be displayed at the 2008 North American International Auto Show is the 2009 Cadillac CTS-V. The CTS-V is propelled by an engine closely related to the LS9 and carrying the designation LSA.

Like the LS9, the LSA is an aluminum block 6.2L V-8 with an Eaton 6th generation two-rotor supercharger. The basic configuration matches the LS9 with the blower sitting in the valley of the block. An air to liquid intercooler sits on top of the supercharger. Differences between the two engines are primarily intended to give the Cadillac an extra air of refinement compared to the sports car and result in the LSA "only" producing 550 hp and 550 lb-ft of torque. Read on after the jump to learn about the differences between the LS9 and LSA

The single biggest difference leading to lower output for the Cadillac is the supercharger displacement. While the LS9 has a 2.3L blower, the unit in the CTS-V only displaces 1.9L. Aside from the size, the blower is based on the same four lobe rotor design with 160 degrees of twist to the lobes. The design provides greater efficiency and thirty-five percent less power draw than the previous three lobe design in addition to much quieter operation. The maximum boost pressure is reduced from 10.5 psi to 9.0 psi.

Since the CTS-V had a little more vertical and longitudinal space under the hood than the Corvette, the engineers were able to use a different intercooler. The LS9 intercooler has two separate heat exchanger units that are split on either side of the supercharger outlet. The LSA has a single heat exchanger that is slightly taller but has more efficient airflow. The other packaging difference is the use of a third drive belt dedicated to the supercharger rather than the two belt system used on the ZR1 engine.

The lower pressures mean that some of the material changes that were implemented on the LS9 were not necessary on the LSA. The titanium connecting rods and intake valves are replaced by forged powdered metal and SilChromel, respectively. The exhaust valves on the LSA are not sodium filled either. The exhaust manifolds are cast iron rather than stainless steel as on the LS9 and the main bearing caps are nodular iron rather than steel.

The pistons in the LSA are hyper-eutectic cast aluminum rather than being forged. The piston skirts are polymer coated for improved scuff resistance and reduced NVH. The sumped top design of the pistons is retained, which allows for clearing the valves without machined valve pockets. The continuous surface free of edges helps to avoid hot spots that can contribute to pre-ignition.

The LSA also gets the dual pressure fuel system used in the the LS9, but the top pressure is reduced from 600kPa to 450kPa. The LSA gets the same beefed up block casting, seven-layer head gasket and 12mm head bolts as its big brother. The improved lubrication system including the squirters that spray oil on the bottom of the pistons is also retained. In total, the LSA and LS9 have about 100 new part compared to the LS7 in the current Corvette Z06. Of those, about twenty-five percent are common to both engines.

The end result is an engine that compared with the BMW M5 has 50 hp more at its peak and, more importantly, a much fatter torque curve. At 1,200 rpm the LSA is already producing more torque than the 383lb-ft that the M5 engine makes at its 6,100 rpm peak, and it never really lets up. It's the kind twisting force that gives you a shove in the back and just keeps pushing and pushing as long as the driver has the nerve to keep his or her right foot planted.

Re: 09 CTS-V LSA Engine -> 09 ZR-1 LS9 Engine

Originally Posted by Kidhummer

...The exhaust manifolds are cast iron rather than stainless steel as on the LS9...

I was just comparing the two between their respective exploded pictures yesterday. The LSA's don't look half bad for cast items (no sharp turns), but the LS9's collector looks cavernous by way of comparison...wonder how much this, along with appropriately sized downpipes on back might be worth on their own (assuming everything would even fit--the LSA's oil pump or something is protruding from the sump)...

Re: 09 CTS-V LSA Engine -> 09 ZR-1 LS9 Engine

A motor that can rev to 8650 is a sign of superior technology and design.
It has nothing to do with american vs foreign, lol. Read: It is a good thing, not a bad thing.

In real life, this motor can drive the Audi around corners without changing gears as often since it makes power along a wider band. This reduces the need for extra displacement and makes the vehicle lighter, a double benefit.

Re: 09 CTS-V LSA Engine -> 09 ZR-1 LS9 Engine

Jpjr
Reving an engine to 8650 rpm will wear it out quicker. Why do you think domestic autos run 200,000 miles with no problem these days. In the 60's 100,000 miles was a real milestone. Then an engine was running 3000rpm at 60 (My 1968 Olds 442 ran 3400 at 60) today, my V runs 1800. Better gas mileage and less wear. (Computer controlled fuel injection helped as well.)
I also remember a friend with a 1968 Z28 would rev it to 8000 and drop the clutch when racing. It is just a matter of valve train and supporting bottom end. The problem then becomes you have to drive around at 3000+ to make any power.
Race cars are running around 19,000 rpm to make their power because they have tiny displacement. Goes back to what I said, displacement or RPM.
The gas expanding in a cylinder can't read Chev, Audi or BMW.

Re: 09 CTS-V LSA Engine -> 09 ZR-1 LS9 Engine

A motor that can rev to 8650 is a sign of superior technology and design.
It has nothing to do with american vs foreign, lol. Read: It is a good thing, not a bad thing.

In real life, this motor can drive the Audi around corners without changing gears as often since it makes power along a wider band. This reduces the need for extra displacement and makes the vehicle lighter, a double benefit.

Not necessarily true.

A higher rev limit does not necessarily equate to a wider power band. More often than not, a high revving engine will be a peaky motor. Its power production will be limited to the upper ranges, thereby, requiring you to work the gears in order to keep the engine in its power range (which is not itself a bad thing, as that is part of the fun).

Also, any lighter weight imparted by a lower displacement is often lost to the addition of the "superior" overhead cams and associated components - right on top of the engine, no less.

I would like to be able to rev the engine to at least 6500, though. If not higher.

Re: 09 CTS-V LSA Engine -> 09 ZR-1 LS9 Engine

An LSA with 8600 rpm redline will perform better than an LSA with 6200 rpm redline if it is built correctly, that is all I'm trying to say.

But you can't compare power, because high rev motors don't require the same displacement. They generate power and performance from high engine speeds, avoiding increasing the size of the engine or using a turbo/super charger, which require increases in weight and fuel consumption.

For people citing reliability, once again I don't think that BMW is having a problem losing money on warranty costs. Adding a blower to the LSA strains engine internals in a similar manner to revving, it all comes down to reliability. It's sort of a funny argument given nameplate reputations for quality.